Boston Bombing aftermath, any similarity to the Lincoln assassination aftermath?

[My Name Is Kate]

Classmates and friends of the younger bombing suspect all seem to agree what a nice a guy he was/is, and they can't believe he would do such a thing. They wonder if he was brainwashed by his older brother. The cops now think his throat wound may have been self-inflicted in a suicide attempt, though it is questionable that any remorse was involved.

I see some similarities with LTP's case. People who knew Powell from childhood couldn't believe he would end up the way he did. And he seems to have been brainwashed into doing what he did, then didn't care whether he lived or died afterwards, and actually preferred to die. Both were very young.

I hope the bombing suspect's interrogators can find out some useful information from him, especially as to how a supposedly otherwise normal person could suddenly turn into something very much like a fiend.